347 Bar (Stainless)
Iron 68%, Chromium 18%, Nickel 11%, Columbium+Tantalum 10 x Carbon minimum
Standard Inventory Specifications
• AMS 5646, PWA-LCS
• ASTM-A 193
• ASTM-A 276
• ASTM-A 479
• QQS 763
• Line marked over 0.5 inches in diameter
• Predominantly produced by AOD process. Annealed, centerless ground or rough turned.
• Lengths: 10-12 feet
Type 347 is a columbium/tantalum stabilized austenitic chromium-nickel stainless steel which was developed to provide an 18-8 type alloy with improved intergranular-corrosion resistance. Type 347 is stabilized against chromium carbide formation by the addition of columbium and tantalum. Since columbium and tantalum have a stronger affinity for carbon than chromium, columbium-tantalum carbides precipitate within the grains instead of forming at the grain boundaries. Type 347 should be considered for applications requiring intermittent heating between 800ºF (427ºC) and 1650ºF (899ºC), or for welding under conditions which prevent a post-weld anneal.
Non-magnetic. The corrosion resistance of Type 347 stainless steel is similar to Type 304 stainless steel. Type 347 is used for welded equipment which cannot be annealed and for equipment which is operated between 800-1500˚F (427-816˚C). The elevated temperature stress rupture and creep strength of Type 347 are higher than Type 304 stainless steel. The room temperature yield strength and tensile strength are approximately 35,000 psi and 85,000 psi, respectively.
The hardness of Aerodyne stock is typically 170 BHN and is supplied in the fully annealed condition. Type 347 is not hardenable through heat treatment, but small sections can be cold work hardened. Room temperature yield strength is typically 40,000 psi with tensile strength of 90,000 psi.
RATING: 80% of B-1112
TYPICAL STOCK REMOVAL RATE: 90 surface feet/minute with high speed tools.
Type 347 machines with tough and stringy chips and has a high rate of work hardening and requires a rigid set-up, plenty of power and positive cuts. Use as heavy a cut as possible to prevent surface work hardening and glazing.
Density: 0.290 lbs/in3, 8.03 g/cm3